The invention relates to a novel countersink. More particularly, the invention concerns a countersink which can operate in dual direction.
Countersinks are most commonly used in order to enlarge the outer end of a hole or cavity, in order to receive the head of a screw.
Another common use of countersinks, is to remove burrs formed on the rims of holes, while the hole is being formed by drilling or by other known means. Rims of holes formed in metal plates are easily accessible from both sides of the hole by known countersinks, which are substantially of conical shape with several cutting edges extending along the conical surface, having a relief angle therewith. The cutting edges in known conical countersinks are all facing same direction and therefore can cut while rotating in one direction only, which is a major disadvantage, since the operator has to move his wrist back and forth in order to accomplish the deburring by hand, thus the backward movement in known countersinks, does not contribute to the deburring.
It is the object of the present invention to provide for a hand operated countersink adapted to remove burrs from holes formed by drilling by both forward and backward circular motion of the tool.